Utilization of the plant methionine sulfoxide reductase B genes as selectable markers in Arabidopsis and tomato transformation

Plant transformation is an important tool for basic research and agricultural biotechnology. In most cases, selection of putative transformants is based on antibiotic or herbicide resistance. Overexpression of plant genes that provide protection from abiotic or biotic stresses can result in a conferred phenotype that can be used as a means for selection. We have demonstrated herein that specific methionine sulfoxide reductase B (MsrB) genes that are overexpressed in transgenic plants may constitute a new selectable marker with concomitantly increased tolerance to methyl viologen (MV) treatment. Arabidopsis transformants overexpressing cytosolic MsrB7, MsrB8 or MsrB9 are viable and survive after MV selection. To establish whether these native plant origin genes serve as new non-antibiotic markers that can be applied to crop transformation, tomato cotyledons were used as transformation materials. MsrB7 transgenic tomato plants were successfully obtained by Agrobacterium-mediated transformation and selection on medium supplemented with MV. We suggest that specific MsrB genes that are overexpressed in transgenic plants may constitute a new selectable marker with increased tolerance to oxidative stress concomitant with MV treatment.